title: Prediction and monitoring of the response to chemoradiotherapy in oral squamous cell carcinomas using a pharmacokinetic analysis based on the dynamic contrast-enhanced MR imaging findings.
abstract: OBJECTIVE
  To evaluate whether a pharmacokinetic analysis is useful for both predicting and monitoring the response to chemoradiotherapy (CRT) in oral cancer.
  
  
  METHODS
  Patients with oral squamous cell carcinoma treated with preoperative CRT and surgery were enrolled. They underwent dynamic contrast-enhanced MRI before (n = 23), and after CRT (n = 20). We estimated four parameters: arrival time of contrast medium (TA), exchange rate constant from the extracellular extravascular space (EES) to plasma (k(ep)), elimination of contrast medium from the central compartment (k(el)) and an amplitude scaling constant (AH) using the Brix model. The histological evaluation of the effects of CRT was performed according to Ohboshi and Shimosato's classification. We analysed the correlation between the parameters and the histological evaluation.
  
  
  RESULTS
  The pre-CRT AH between the responders and non-responders was significantly different (P = 0.046), however, the three parameters (TA, K(ep), K(el)) were not significantly different among the groups (P = 0.76, P = 0.60, P = 0.09). As AH decreased, the tumour response improved. The change in the AH between the pre- and post-CRT of responders was significantly higher than that of non-responders (P = 0.043).
  
  
  CONCLUSIONS
  The AH, which is affected by the ratio of the EES, was an important parameter for predicting and monitoring the tumour response to CRT.
authors.affiliation: Department of Oral and Maxillofacial Radiology, Faculty of Dental Science, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan. chikui@rad.dent.kyushu-u.ac.jp
authors.forename: Toru
authors.initials: T
authors.lastname: Chikui
authors.forename: Shintaro
authors.initials: S
authors.lastname: Kawano
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kawazu
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Hatakenaka
authors.forename: Syouzou
authors.initials: S
authors.lastname: Koga
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ohga
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Matsuo
authors.forename: Syunya
authors.initials: S
authors.lastname: Sunami
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sugiura
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Shioyama
authors.forename: Makoto
authors.initials: M
authors.lastname: Obara
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yoshiura
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000532:radiotherapy*; D003131:Combined Modality Therapy; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D003287:Contrast Media; D019786:Gadolinium DTPA